Adjustable lamp



FIG. 1 is left side elevational view of an adjustable lamp showing our new design;

FIG. 2 is a top plan view thereof;

FIG. 3 is a bottom plan view thereof;

FIG. 4 is a front elevational view thereof; and

FIG. 5 is a rear elevational view thereof. 

The ornamental design for an adjustable lamp, as shown and described. 